* [varLib.models] Add test for modeling rounding error
Tests https://github.com/fonttools/fonttools/pull/2214
If you flip demo to True, it does a slower test and demos the new error as well
as the error the old code was producing (ie. rounding deltas post-modeling).
Indeed, the new error is always capped by 0.5 as expected, whereas the old one
was unbounded. Here's the worst-case error of the bad code:
...
240 0.42 4.8
...
240 is just the line number. 0.42 is new error. 4.8 is old error.
* turn test_modeling_error into a parametrized pytest test
Like the other test methods in the same module, all those whose name starts with 'test_' are automatically discovered and run by pytest which is our default test runner. So there is no need to call the test method itself in the top-level module scope. One simply runs the test via pytest. To execute this specific test method one can do 'pytest Tests/varLib/models_test.py::test_modeling_error'.
* use pytest markers to mark specific test as 'slow'
So that one can optionally deselect tests marked with specific marker by passing -m option (e.g. to deselect 'slow' tests, pytest -m 'not slow' ...).
https://docs.pytest.org/en/stable/mark.html#registering-markshttps://docs.pytest.org/en/stable/example/parametrize.html#set-marks-or-test-id-for-individual-parametrized-test
* [varLib/models_test] Comment out non-test code
Co-authored-by: Cosimo Lupo <clupo@google.com>
* Replaced all from ...py23 import * with explicit name imports, or removed completely when possible.
* Replaced tounicode() with tostr()
* Changed all BytesIO ans StringIO imports to from io import ..., replaced all UnicodeIO with StringIO.
* Replaced all unichr() with chr()
* Misc minor tweaks and fixes
not only base should be at 0, but min/max respectively at -1.0 and +1.0.
that's how varLib constructs models internally, so update test case to reflect that
Oops. Was introduced when I last changed modeling.
The problem was, for checking that a previous master m is outside the current
influence box of the current master, I was doing "not (lower < m[loc] < upper)".
This is wrong, where lower,peak,upper is the support of previous master.
This fails if lower == peak == m[loc], or m[loc] == peak == upper.
Fixes https://github.com/fonttools/fonttools/issues/1269#issuecomment-397655016
Improve varLib model algorithm.
This, basically means any varfont built that had an unusual master
configuration will change when rebuilt.
Here's a good test: a two-axis with 8 masters at unusual locations:
2-----------------5----------3
| |
| 7 |
| |
| 6 |
| |
| |
| |
0-----------4----------------1
Previously, the reach of master 3 (Black Extended) would
have started from A=.4, ie, the A position of master 4.
It now correctly starts from 0. Same thing with masters
after it. Ie, master 5 gets a span on the A axis from
0 to 1, whereas before it was getting from .4 to 1.
Previously, the on-axis masters always cut the space. They
don't anymore. That's more consistent, and fixes the main
issue Erik showed at TYPO Labs 2017. Same issue was also
causing the reach of master 3 to be limited, which I think
is the issue being discussed in the linked issue. Both should
be fixed.
It's hard to describe exactly what happened before / after.
Best to read the actual support values:
Before:
Sorted locations:
$ ./fonttools varLib.models 0,0 0,1 1,0 1,1 .4,0 .6,1 .5,.5 .7,.7
[{},
{'A': 0.4},
{'A': 1.0},
{'B': 1.0},
{'A': 1.0, 'B': 1.0},
{'A': 0.6, 'B': 1.0},
{'A': 0.5, 'B': 0.5},
{'A': 0.7, 'B': 0.7}]
Supports:
[{},
{'A': (0.0, 0.4, 1.0)},
{'A': (0.4, 1.0, 1.0)},
{'B': (0.0, 1.0, 1.0)},
{'A': (0.4, 1.0, 1.0), 'B': (0.0, 1.0, 1.0)},
{'A': (0.4, 0.6, 1.0), 'B': (0.0, 1.0, 1.0)},
{'A': (0.4, 0.5, 1.0), 'B': (0.0, 0.5, 1.0)},
{'A': (0.5, 0.7, 1.0), 'B': (0.5, 0.7, 1.0)}]
After:
$ ./fonttools varLib.models 0,0 0,1 1,0 1,1 .4,0 .6,1 .5,.5 .7,.7
Sorted locations:
[{},
{'A': 0.4},
{'A': 1.0},
{'B': 1.0},
{'A': 1.0, 'B': 1.0},
{'A': 0.6, 'B': 1.0},
{'A': 0.5, 'B': 0.5},
{'A': 0.7, 'B': 0.7}]
Supports:
[{},
{'A': (0, 0.4, 1.0)},
{'A': (0.4, 1.0, 1.0)},
{'B': (0, 1.0, 1.0)},
{'A': (0, 1.0, 1.0), 'B': (0, 1.0, 1.0)},
{'A': (0, 0.6, 1.0), 'B': (0, 1.0, 1.0)},
{'A': (0, 0.5, 1.0), 'B': (0, 0.5, 1.0)},
{'A': (0.5, 0.7, 1.0), 'B': (0.5, 0.7, 1.0)}]
TODO: We should add this as a test case.
There's another improvement I want to make, but that's separate.
